Problem: A bag contains $8$ red jelly beans, $11$ green jelly beans, and $4$ blue jelly beans. If a jelly bean is randomly chosen, what is the probability that it is not blue?
Answer: There are $8 + 11 + 4 = 23$ jelly beans in the bag. There are $4$ blue jelly beans. That means $23 - 4 = 19$ are not blue. The probability is $ \frac{19}{23}$.